The present invention relates to a camshaft adjusting device, in particular a passive camshaft adjusting device, for controlling the phase position of a camshaft with a rotary actuator including a stator and an axially displaceable rotor and a gear mechanism arranged between two shafts for adjusting their relative angular positions.
It is known to change the phase position of a camshaft of an internal combustion engine by means of camshaft adjusting devices. It is also known to adjust the phase position by means of a brake. The variable moment of the brake at the control input of the gear mechanism of the camshaft adjusting device is utilized to change the phase position of the camshaft. Application of the brake causes the control shaft to slow down and therefore changes the phase position to advanced, for example via a negative gear mechanism. If the brake is released, the control input accelerates because of the load moment of the camshaft, and the phase position is retarded. At a constant phase position, the control shaft has to be kept at the rotational speed of the camshaft in such a manner that there is no relative movement in the gear mechanism. During starting of the internal combustion engine, at low rotational speeds and if the brake fails, the camshaft adjusting device has to be locked in a position customarily situated between end stops. Locking is also desirable in the event of failure of parts of the system, such as the brake, the control unit, the contact connection means, the sensor technology and the like, in order to permit emergency operation of the vehicle.
Laid-open specification DE 102 24 446 A1 discloses an electric adjusting device, in which a relative angular position of two shafts is brought about via a relative rotation of a control shaft which is operated by a rotor of an electromagnetic adjustment drive. If the adjustment drive is not energized, the axially movable rotor is operatively connected to a drive shaft, and therefore a relative rotation of the shafts with respect to each other is prevented. When the adjustment drive is energized, the operative connection between rotor and drive shaft is released by an axially effective magnetic force and the rotor can rotate the control shaft.
It is the principal object of the present invention to provide a camshaft adjusting device and a rotor for a camshaft adjusting device, which, while being cost effective and compact, is capable of locking the camshaft adjusting device.